Created: Aug. 28, 2015, 7:40 p.m.

This dataset has been used for ground truth validation of the snow inspector software (http://apps.hydroshare.org/apps/snow-inspector).On two days, May 2 and May 9, 2015, 36 areas in the Yellowstone National Park area were visited. The snow inspector software was used to identify the MODIS satellite pixel boundaries at a 1:10,000 scale . For each location we identified between 1 and 8 pixels and estimated the percentage of snow-covered area on the ground. We selected locations with open ground, partially tree-covered ground, and ice-covered lakes. The total number of ground validation pixels was: 102 pixels on May 2, 2015, and 82 pixels on May 9, 2015 (total 184 pixels). Out of the total 184 pixels, Twenty-eight pixels were inspected both on May 2 and on May 9. The attached csv file has the following fields: Location (name of the location), PIXEL_X and PIXEL_Y (satellite pixel identifier), PIXEL, pixel number at the location, X1.May (satellite snow cover percentage on 1st May 2015), X2.May (satellite snow cover percentage on 2nd May 2015), MillerLo (low -bound estimate of snow cover percentage from ground observation), MillerHi (high estimate of snow cover percentage from ground observation), Landcover (type of land cover), Latitude, Longitude (latitude and longitude are in WGS 1984 in decimal degrees).

Created: Oct. 14, 2015, 6:27 p.m.

Cross country skiing trips from 6-9 February, 2015 from Czechia, downloaded using the Garmin Connect (connect.garmin.com/explore) API. I used the category "cross country skiing" to retrieve a total of 150 gpx routes. The routes were converted from the .gpx format to a line shapefile (.shp). Each feature represents one trip with information about trip start time and trip end time. The projection of the shapefile is WGS1984.

Created: July 21, 2015, 4:36 p.m.

The attached .csv file contains snow depth reports received from volunteer observers from January 2014 until March 2015 from Czechia. The file has the following data fields:DATE: The date of the snow reportTIME: The local time of the snow report in (UTC+1)LATITUDE: The latitude in WGS84LONGITUDE: The longitude in WGS84SITE: The name of the place where the snow depth was observedSNOW_DEPTH_CM: The reported snow depth in centimeters. If the value is 0.5, then a trace of snow (incomplete snow coverage) was reported.

The script used for generating the file is accessible on github:https://github.com/jirikadlec2/global-snow/blob/master/user_reports/snow.py

Created: Dec. 29, 2015, 11:42 p.m.

Ski tracks in Czechia and surrounding regions collected by cross-country skiers using the Garmin Connect network.The track data was quality-controlled. The attached shapefile contains data from the period 2012 - 2015.

Created: Feb. 5, 2016, 8:48 a.m.

Ski tracks in Czechia and surrounding regions collected by cross-country skiers using the Garmin Connect network.The track data was quality-controlled, and tracks recorded on major road and on artificial snow were removed. The attached shapefile contains data from the period 2012 - 2015.

Created: Feb. 7, 2016, 1:14 a.m.

Cross-country skiing tracks in Czechia and surrounding regions, retrieved from the Strava API. These tracks were recorded by mobile device. The tracks were quality-controlled to check for gaps, track on major road, and track on artificial snow.